The concern with telling Jen anything big was that her friend wasn't always great at keeping secrets from other people. Especially when they happened to be the big kind of secret that said other people would be just as excited to find out about.
Which was the whole reason that Celeste didn't want to tell her anything in the first place. She would likely go and tell any of their mutual friends who would listen about what Celeste had gotten herself into.
It wasn't something bad but it would become worse if Bane found out that more and more people were going to be wanting to come around his house.
Celeste had to use threats and bribes to get Jen to solemnly agree that she wasn't going to breathe a word to anyone else. Well... Most anyone else. She didn't think that there would be much of a problem if Liam heard about it.
